opto electronics ( et – 421) fall-213 lecture# 01 introduction “optical communication” engr....
TRANSCRIPT
Opto Electronics(ET – 421)FALL-213
Lecture# 01Introduction “optical
communication” Engr. Tasleem Kausar
Text Books
• Gerd Keiser, “Optical Fiber Communications”, McGraw–Hill, 3/e
• G. P. Agrawal, “Fiber-Optic Communication Systems” Wiley, 3/e
• Richard S. Quimby,“Photonics and Lasers An Introduction”
Grading Policy
• Assignments, Quizzes, Attendance, Computer Simulations(10%)
• Course Project(10%)• Mid Semester Exams(20%)• End Semester Exams(60%)
Miscellaneous
► Web Page: Course management system(CMS)
► Office Hours : Monday (1:00 PM - 3:30 PM) ►Contact: [email protected]
Why Optical Communications
• In eight century B.C Greeks use fire to communicate
• Electrical Systems , signals are supper imposed onto the carrier(Electromagnetic waves)
• Problem ???• Data rate• Distance
Wavelength Bands of Interest
• 50 nm (UV) – 100 μ m (IR)• 400 nm – 700 nm (visible region)• 800 nm – 1600 nm (1.55μm) range
Choice of wavelength
• First Window(820nm-880nm)• Second Window(1200nm-1320)• Third Window(1550nm-1610nm)
Optical Communications Benefits
• Extremely wide bandwidth: High carrier frequency ( a wavelength of 1552.5 nm corresponds to a center frequency of 193.1 THz)
• Small size & light weight• Immunity to Interference: Electromagnetic
interference (high voltage transmission lines, radar systems, power electronic systems, airborne systems, ...)
• Signal Security
Optical Communications Benefits
• Lack of EMI cross talk between channels• Ruggedness and Flexibility• Low Transmission loss (0.25 to 0.3 dB/km)• System Reliability and Ease of Maintenance: high
performance• active & passive photonic components such as
tunable lasers, very sensitive photo detectors, couplers, filters,
• Low Cost systems for data rates in excess of Gbps